Pancreatic Acinar Cell Carcinoma with Multiple Liver Metastases Effectively Treated by S-1 Chemotherapy

Pathological complete response with FOLFIRINOX therapy for recurrence of pancreatic acinar cell carcinoma

Pancreatic acinar cell carcinoma (PACC) is a very rare subtype of pancreatic cancer. Due to small number of patients, no standard chemotherapy protocol has been established. We experienced an extremely rare case of PACC with liver metastasis that showed a pathological complete response after modified FOLFIRINOX (mFFX) therapy. A 42-year-old man who underwent distal pancreatectomy for an 80 mm tumor at the pancreatic tail 3 years ago was referred to our hospital in September 2017 for the treatment of a recurrent liver tumor. Percutaneous biopsy revealed an acinar-neuroendocrine carcinoma, similar to the surgical specimen. He received eight cycles of irinotecan plus cisplatin chemotherapy. However, the tumor increased in size, and treatment was switched to mFFX therapy. The tumor in the liver shrank remarkably after nine cycles of mFFX therapy. Conversion surgery was selected, and the patient underwent hepatic left and caudate lobectomy 8 months after administration of mFFX. The resected specimen showed no viable tumor cells, indicating a pathological complete response. The histological diagnosis was reconsidered, and PACC was finally diagnosed via an additional immunohistological review. The patient has remained well with no recurrence for 6 years after surgery. This study is the first to report a case of pathological complete response with mFFX therapy for the recurrence of PACC.

The Utility of Endoscopic-Ultrasonography-Guided Tissue Acquisition for Solid Pancreatic Lesions

Endoscopic-ultrasonography-guided tissue acquisition (EUS-TA) has been widely performed for the definitive diagnosis of solid pancreatic lesions (SPLs). As the puncture needles, puncture techniques, and sample processing methods have improved, EUS-TA has shown higher diagnostic yields and safety. Recently, several therapeutic target genomic biomarkers have been clarified in pancreatic ductal carcinoma (PDAC). Although only a small proportion of patients with PDAC can benefit from precision medicine based on gene mutations at present, precision medicine will also be further developed for SPLs as more therapeutic target genomic biomarkers are identified. Advances in next-generation sequencing (NGS) techniques enable the examination of multiple genetic mutations in limited tissue samples. EUS-TA is also useful for NGS and will play a more important role in determining treatment strategies. In this review, we describe the utility of EUS-TA for SPLs.

Acinar Cell Carcinoma with Morphological Change in One Month

A 64-year-old man was admitted to our hospital to undergo examination of a pancreatic tumor accompanied by sudden epigastric pain. The tumor had a well-defined oval shape that was mostly less enhanced, with the exception of part of the tumor on the pancreatic head side, on contrast enhanced (CE)-CT. However, CE-CT performed one-month later revealed that the viable part of the tumor grew toward the pancreatic tail with the reduction of necrotic tissue. We performed distal pancreatectomy and the tumor was diagnosed as acinar cell carcinoma (ACC). One important characteristic of ACC is that it may develop morphological changes within a short period of time.

Metastatic Acinar Cell Carcinoma of the Pancreas: A Retrospective Cohort Study on Systemic Chemotherapy and Review of the Literature

OBJECTIVES

Acinar cell carcinoma of the pancreas (pACC) forms a rare subgroup of pancreatic tumors. We report on our institutional experience with systemic first- and further-line therapy in patients with metastatic pACC and embed our findings in a review of the literature.

METHODS

Patients with stage IV pACC who started systemic treatment between 2008 and 2019 at our institution were identified via our institutional database. Clinical data were extracted from the patients' electronic data records. Survival times were calculated by the Kaplan-Meier method.

RESULTS

Six patients received a fluoropyrimidine- and oxaliplatin-containing first-line treatment, and 4 patients were started on gemcitabine-based protocols. Median progression-free survival was 4.8 months [95% confidence interval (CI), 3.3 to not available (n.a.)], and median overall survival was 15.3 months (95% CI, 10.1 to n.a.). Residual survival for second-line treatment was 2.1 months (95% CI, 1.3 to n.a.), although 1 patient experienced almost complete remission under targeted therapy.

CONCLUSIONS

The most encouraging and deep responses result from poly-chemotherapy with leucovorin, 5-fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX), which seems to be the appropriate choice in fit patients. Gemcitabine monotherapy seems without substantial activity in pACC. Whenever possible, patients with pACC should be screened for targetable mutations.